Flexible rotor for fluid pumps

ABSTRACT

A fluid pump comprises a chamber the interior of which has parallel opposed walls and a peripheral wall, a rotor eccentrically mounted within the chamber and having two opposed faces engaging with the parallel opposed walls of the chamber and a peripheral surface a part of which slidably engages the peripheral wall of the chamber as the rotor rotates. The chamber is provided with inlet and outlet ports between which a vane is reciprocally mounted in the peripheral wall of the chamber, and the vane has a spring urging it into engagement with the periphery of the rotor and projects into an enclosed space which is formed outside the chamber and which is placed into direct communication with the outlet port of the fluid pump by a passage. The rotor is formed with an axial open-ended slot which extends inwardly from an edge of the rotor between the part of the rotor which engages the peripheral wall of the chamber and the axis of rotation of the rotor.

limited States Patent [191 Primary ExaminerC. J. l-iusar Assistant Examiner-Leonard Smith Attorney, Agent, or FirmMawhinney & Mawhinney Wilcox Dec. 3, 1974 FLEXIBLE ROTOR FOR FLUID PUMPS [57] ABSTRACT [75] Invent Kenneth J h Wil C d, A fluid pump comprises a chamber the interior of C diff wales which has parallel opposed walls and a peripheral wall, a rotor eccentrically mounted within the cham- [73] Asslgnee: Accessones Hayes ber and having two opposed faces engaging with the Mlddlesex England parallel opposed walls of the chamber and a periph- 22 Filed; Oct 24 1972 eral surface a part of which slidably engages the peripheral wall of the chamber as the rotor rotates. The [21] Appl. No.: 299,776 chamber is provided with inlet and outlet ports be i 1 tween which a vane is reciprocally mounted in the pe- 301 Foreign Application p or Data riph eral wall of the chamber, and the vane has a 0m. 25 1971 Great Britain 49533/71 spmg rgmg engagement the Penphery of the rotor and projects into an enclosed space which is formed outside the chamber and which is placed into 6 gg direct communication with the outlet port of the fluid i p p y a p g The rotor is formed with an axial [58] Field of Search 418/156, 157, 248, 249 Opemiinded Slot which extends inwardly from an g of the-rotor between the part of the rotor which en- [56] Refernces Cited gages the peripheral wall of the chamber and the axis UNITED STATES PATENTS of rotation of the rotor. 1,796,535 3/1931 Rolaff 418/249 X 2,050,473 8/1936 Steinmann 418/248 X 4/1964 Brown 418/248 X 4 Claims, 2 Drawing Figures I FLEXIBLE ROTOR FOR FLUID PUMPS According to the inventionthere is provided a fluid pump comprising a chamber the interior of which has parallel opposed walls and a peripheral wall, a rotor mounted within the chamber and having two opposed faces thereof permanently in sliding engagement with the parallel opposed walls of the chamber and a peripheral surface a part only of which slidably engages .the peripheral wall of the chamber as the rotor rotates, an inlet port and an outlet port in the chamber, and a vane reciprocally mounted in the peripheral wall of the chamber, which vane slidably engages the opposed parallel walls of the chamber and has means urging it into engagement with the periphery of the rotor, the vane being disposed between the inlet and outlet ports. Thus as the rotor rotatesthe vane and rotor together divide the chamber into two parts containing the inlet port and outlet port respectively. During a single rotation of the rotor one part of the chamber increases in volume as the otherpart decreases and this provides the pumping action the rotor drawing fluid through the inlet port into the increasing 'volume and pushing fluid through the outlet port from the decreasing volume part.

The means urging the vane into engagement with the periphery of the rotor may comprise spring means. Alternatively or. additionally a part of the vane outside the chamber may project into a space having means for placing the spacein' communicationwitha source of fluid under pressure when the pump is operating. The fluid pressure in the space thus tendsto urge the vane into engagement with the periphery of the rotor. For example there maybe provided a passage placing the space into communication with the outlet port.

The chamber may be of circular configuratiomthe rotor being eccentrically mounted for rotation about the central axis of the chamber. In this case the rotor also may be of circular configuration.

In any of the above arrangements the inlet and outlet ports are preferably disposed in the peripheral wall of the chamber.

The following is a more detailed description of two embodiments of the invention reference being made to the accompanying drawings in which: 4

FIG. 1 is a side view of one form of pump a cover plate being removed to show the interior construction of the pump; and 1 FIG. 2 is a similar view to FIG. 1 of an alternative form of pump.

Referring to FIG. 1 the pump comprises a casing mouldedv from plastics material and incorporating three mounting lugs 11.

There is formed in the casing a chamber 12 having a circular peripheral wall and two parallel opposed walls one of which is formed in the casing 10 and the other of which is provided by a cover plate (not shown) which fits over the casing 10.

Communicating with the interior of the chamber are an inlet port 13 and an outlet port 14 leading to slots 15 and 16 respectively formed in ears 17 and 18 inte- 1 grally moulded with the casing 10. The slots 15 and 16.

are in communication with inlet and outlet conduits (not shown) on the aforementioned cover plate the conduits being arranged for connection through flexible tubing with a water reservoir and outlet nozzles respectively. I

A circular cross-section cylindrical rotor 19 which may be formed from brass or other suitable material is eccentrically mounted within the chamber 12 for rotation about the central axis of the chamber. The dimensions of the rotor 19 are such that a part of the periphery of the rotor sweeps aroundfithe peripheral wall of the chamber 12 as the rotor rotates. The rotor is'rotated by a shaft driven from a small electric motor (not shown). A slot 20 is formed in theficasing 10 between the inlet and outlet ports 13 and l4 and a vane 21 is closely slidable within the slot 20 and engages the periphery of the rotor 19. The end of the vane 21 remote from the rotor 19 projects into a rectangular cavity 22 formed in the casing 10 and the vane 21 is urged towards the rotor 19 by a helical compression spring 23 disposed within the cavity 22. A passage 24 also formed in the casing 10 places the cavity 22 in communication with the outlet slot 16 from the chamber 12.

The part of the casing containing the chamber 12,

slots 15 and 16, cavity 22 and passage 24 is raised slightly above the surface of the rest of the-casing 10 as indicated at 25 so as to provide a good'fluid-tight seal between the casing and the aforementioned cover plate when the cover plate is secured in position. The cover plate is formed with three lugs corresponding to the lugs 11 by means of which it is secured, for example by bolts or rivets, to the casing 10. The cover plate is formed around its periphery with a shaped flange which projects at right angles from the general plane of the cover plate and fitsover the periphery of the casing 10.

I In operation as the rotor 19 rotates clockwise from the position shown in FIG. 1 it, together with the vane 21, will divide the chamber 12into two parts one containing the inlet l3 and the other containing the outlet port 14. As the rotor rotates clockwise the part containing the inlet port 13 will increase in volume and the part containing the outlet port 14 will decrease so that fluid from the reservoir will be drawn into the chamber behind the rotor and fluid in the chamber will be forced out of the outlet port 14in front of the rotor. Fluid under pressure will also pass along the passage 24 to the cavity 22 and will assist the spring 23 in urging in FIG. 1 the inlet port 13 will, for a very brief period,

be in communication with the outlet port 14. It is found that for normal requirements the speed of rotation of the rotor prevents any appreciable flow back from the chamber through the inlet port and thus valves are not required.

The arrangement shown in FIG. 2 is generally similar in principle to the arrangement of FIG. 1 and like parts have like'reference' numerals. However inrthe arrangement of FIG. 2 the slots 15 and 16 are replaced by passages 27 and 28 respectively in elongated parts 29 and 30 integrally moulded with the casing 10 it thus being unnecessary to provide such passages in the cover plate.

It will be seen also that in the arrangement of FIG. 2 the rotor 19 is formed with an axially extending slot 31. Provision of the slot permits the part of the rotor 19 which is in engagement with the wall of the chamber 12 to flex slightly with respect to the main part of the rotor as it rotates. This permits greater manufacturing tolerances in the rotor and chamber and ensures that the rotor remains in good sealing engagement with the wall of the chamber.

In the above arrangements it will be appreciated that the vane 21 will reciprocate rapidly to and fro, and into and out of the cavity 22, as the rotor 19 rotates. In the case where the cavity 22 is in communication with the outlet port 14 through the passage 24, this reciprocating movement of the vane 21 will give a pumping action due to fluid being forced out of the cavity 22 by movement of the vane 21 into the cavity. This will augment the pumping action derived from the rotation of the rotor 19 and can increase the overall efficiency of the pump by a significant amount.

I claim:

1. A fluid pump comprising:

a circular chamber the interior of which has parallel opposed walls and a peripheral wall;

an inlet port and an outlet port communicating with said chamber;

a vane reciprocally mounted in said peripheral wall of said chamber between said inlet and outlet ports for sliding engagement with said opposed parallel walls of said chamber;

a circular rotor eccentrically mounted within said chamber and having two opposed faces thereon permanently in sliding engagement with said parallel opposed walls of said chamber and a peripheral surface a part only of which slidably engages said peripheral wall of said chamber as the rotor rotates eccentrically about the central axis of said chamber;

means urging said vane into engagement with the periphery of said rotor;

an enlcosed space outside said chamber into which a part of said vane projects;

and a passage placing said space into direct communication with said outlet port of the fluid pump;

characterized in that said part of the rotor which slidably engages said peripheral wall of the chamber is resiliently flexible towards and away from the axis of rotation of the rotor;

and in that the rotor is formed with an axial open ended slot which extends inwardly from an edge of the rotor between said port of the rotor which engages said peripheral wall of the chamber and the axis of rotation of the rotor.

2. A fluid pump comprising:

a circular chamber the interior of which has parallel opposed walls and a peripheral wall;

inlet and outlet ports formed in said peripheral wall of said chamber and communicating therewith;

a vane reciprocally mounted in said peripheral wall of said chamber between said inlet and outlet ports for sliding engagement with said opposed parallel walls of said chamber;

a circular rotor eccentrically mounted within said chamber and having two opposed faces thereon permanently in sliding engagement with said paral- .lel opposed walls of said chamber and a peripheral surface a resiliently flexible part of which slidably engages said peripheral wall of said chamber as the rotor rotates eccentrically about the central axis of said chamber;

an axial open ended slot formed in said rotor to extend inwardly from an edge thereof between said resiliently flexible part of the rotor and the axis of rotation of the rotor;

means urging said vane into engagement with the periphery of said rotor;

an enclosed space outside said chamber into which a part of said vane projects;

and a passage placing said space into direct communication with said outlet port of the fluid pump.

3. A fluid pump according to claim 1 wherein said passage conducts a part only of the pressurized fluid output to the rear of the reciprocating vane to assist in maintaining a seal between said vane and said rotor.

4. A fluid pump according to claim 2 wherein said passage conducts a part only of the pressurized fluid output to the rear of the reciprocating vane to assist in maintaining a seal between said vane and said rotor. 

1. A fluid pump comprising: a circular chamber the interior of which has parallel opposed walls and a peripheral wall; an inlet port and an outlet port communicating with said chamber; a vane reciprocally mounted in said peripheral wall of said chamber between said inlet and outlet ports for sliding engagement with said opposed parallel walls of said chamber; a circular rotor eccentrically mounted within said chamber and having two opposed faces thereon permanently in sliding engagement with said parallel opposed walls of said chamber and a peripheral surface a part only of which slidably engages said peripheral wall of said chamber as the rotor rotates eccentrically about the central axis of said chamber; means urging said vane into engagement with the periphery of said rotor; an enlcosed space outside said chamber into which a part of said vane projects; and a passage placing said space into direct communication with said outlet port of the fluid pump; characterized in that said part of the rotor which slidably engages said peripheral wall of the chamber is resiliently flexible towards and away from the axis of rotation of the rotor; and in that the rotor is formed with an axial open ended slot which extends inwardly from an edge of the rotor between said port of the rotor which engages said peripheral wall of the chamber and the axis of rotation of the rotor.
 2. A fluid pump comprising: a circular chamber the interior of which has parallel opposed walls and a peripheral wall; inlet and outlet ports formed in said peripheral wall of said chamber and communicating therewith; a vane reciprocally mounted in said peripheral wall of said chamber between said inlet and outlet ports for sliding engagement with said opposed parallel walls of said chamber; a circular rotor eccentrically mounted within said chamber and having two opposed faces thereon permanently in sliding engagement with said parallel opposed walls of said chamber and a peripheral surface a resiliently flexible part of which slidably engages said peripheral wall of said chamber as the rotor rotates eccentrically about the central axis of said chamber; an axial open ended slot formed in said rotor to extend inwardly from an edge thereof between said resiliently flexible part of the rotor and the axis of rotation of the rotor; means urging said vane into engagement with the periphery of said rotor; an enclosed space outside said chamber into which a part of said vane projects; and a passage placing said space into direct communication with said outlet port of the fluid pump.
 3. A fluid pump according to claim 1 wherein said passage conducts a part only of the pressurized fluid output to the rear of the reciprocating vane to assist in maintaining a seal between said vane and said rotor.
 4. A fluid pump according to claim 2 wherein said passage conducts a part only of the pressurized fluid output to the rear of the reciprocating vane to assist in maintaining a seal between said vane and said rotor. 